Exhibit 10.64


                             SUPPLEMENTAL AGREEMENT

         THIS SUPPLEMENTAL AGREEMENT is entered into this 25th day of April,
1995. by and between NewCorp Resources, Inc. (hereinafter "NCR"), a
corporation organized and existing under the laws of the State of Texas, and
Cap Rock Electric Cooperative, Inc. (hereinafter "Cap Rock"), a corporation
organized and existing under the laws of the State of Texas (collectively the
"Parties").

         WHEREAS, NCR and Cap Rock have entered into a Service Agreement
pursuant to which Cap Rock will purchase electric power and energy from NCR
under NCR's Rate Schedule WP and Tariff for Electric Service on file with the
Federal Energy Regulatory Commission; and

         WHEREAS, NCR and Cap Rock have entered into an Assignment of
Wholesale Power Contract to assign from Cap Rock to NCR the Agreement for
Wholesale Full Requirements Electric Power Service between Southwestern
Public Service Company ("SPS") and Cap Rock dated July 3, 1991, as amended by
the first amendment dated January 22, 1992, (the "SPS Contract"); and

         WHEREAS, NCR is able to satisfy certain of its obligations under the
SPS Contract only if Cap Rock agrees to corresponding obligations to NCR;

         NOW THEREFORE, NCR and Cap Rock, in consideration of these premises
and of the mutual covenants and agreements herein contained, and of the
mutual benefits derived therefrom, thereby agree as follows:

         1.       PURPOSE.

                  This Agreement supplements the terms and conditions found in
                  NCR Rate Schedule WP and the Service Agreement entered into by
                  the Parties on even date herewith. This agreement incorporates
                  all terms and conditions found in Rate Schedule WP and the
                  Service Agreement.

         2.       TERM.

                  Section (6) of the Service Agreement is supplemented as
                  follows:

                  During the period beginning January 1, 2004, and ending
                  December 31, 2013, Cap Rock may elect to terminate the Service
                  Agreement and this Supplemental Agreement early, effective at
                  the end of any calendar year. by giving NCR at least five
                  years' notice before the proposed termination date. In the
                  event of early termination, Cap Rock shall be liable to NCR
                  for any termination or other charges owed by NCR to SPS
                  resulting from Cap Rock's termination and paid by NCR to its
                  power supplier(s).



         3.       SALES TO AND PURCHASES FROM QUALIFYING FACILITIES.

                  In light of the corporate relationship between NCR and Cap
                  Rock, NCR and Cap Rock agree as follows:

                  (a)      During the term of this Agreement, NCR agrees to
                           assume Cap Rock's obligations to purchase electric
                           energy and capacity offered by Qualifying Facilities
                           as required by the regulations set forth in Part 292
                           of the Code of Federal Regulations ("CFR"),
                           promulgated under Sections 201 and 210 of the Public
                           Utilities Regulatory Act of 1978, or the rules and
                           regulations of the Public Utility Commission of
                           Texas, or both, as the case may be.

                  (b)      During the term of this Agreement. Cap Rock agrees to
                           assume NCR's obligations to sell back-up,
                           maintenance, supplementary and interruptible power to
                           Qualifying Facilities as required by the regulations
                           set forth in Part 292 of the CFR, promulgated under
                           Sections 201 and 210 of the Public Utilities
                           Regulatory Act of 1978, or the rules and regulations
                           of the Public Utility Commission of Texas, or both,
                           as the case may be.

Accepted by NCR:                     Accepted by Cap Rock Electric Cooperative:


/s/ Steven E. Collier                /s/ David W. Pruitt
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Signature                            Signature


President                            President/CEO
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Title                                Title


April 25, 1995                       4/25/95
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Date Signed                          Date Signed